Before running the installation script you have to install the dependencies needed for compiling.
sudo apt install make cmake extra-cmake-modules qtdeclarative5-dev libkf5plasma-dev libqt5x11extras5-dev g++ libsm-dev libkf5configwidgets-dev libkdecorations2-dev libxcb-randr0-dev libkf5wayland-dev plasma-workspace-dev
sudo zypper in -y xrandr cmake make gcc gcc-c++ extra-cmake-modules libqt5-qtbase-devel libqt5-qtdeclarative-devel libKF5WindowSystem5 plasma-framework-devel libSM-devel libqt5-qtx11extras-devel libkdecoration2-devel kconfigwidgets-devel kwidgetsaddons-devel kdeclarative-devel
sudo dnf install make cmake extra-cmake-modules qt5-qtdeclarative-devel kf5-plasma-devel qt5-qtx11extras-devel gcc-c++ libSM-devel kf5-kconfigwidgets-devel kdecoration-devel kf5-kitemmodels-devel plasma-workspace-devel kf5-kwayland-devel
sudo pacman -Sy base-devel libxcb plasma-workspace qt5-base qt5-declarative extra-cmake-modules kwindowsystem plasma-framework libdbusmenu-gtk2 libdbusmenu-gtk3
Now you can run the installation script.
sh install.sh